<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title> JavaScript基础 </title>
</head>
<body>
    <button>点我</button>
</body>
<!-- <script src="./js/01.js"></script> -->
<script>
    document.write("你好！")
    var a = "abcdefg";
    console.log(a.charAt(2));
    console.log(a.indexOf("e"));

    var str = a.substring(2 ,5);
    console.log(str);
    console.log(a.substring(3));

    var b ="张三 李四 王五";


</script>
</html>